Url customization using the session-based dash operations

ABSTRACT

There is included a method and apparatus comprising computer code configured to cause a processor or processors to perform obtaining session-based description (SBD) information instructing a client to generate media presentation description (MPD) information of a session, launching an SBD client and passing SBD descriptor information based on the MPD information, controlling generation of a segment uniform resource locator (URL), provision of a timing; and processing of a request for a segment of the video content by at least modifying the segment URL, and providing a segment of the video content based on the modified segment URL.

CROSS REFERENCE TO RELATED APPLICATION

The present application claims priority to provisional applications U.S.63/088,647, filed on Oct. 7, 2020, the contents of which are herebyexpressly incorporated by reference, in their entirety, into the presentapplication.

BACKGROUND 1. Field

The present disclosure is directed to segment uniform resource locators(URL) customization per session and per client using a Session-BasedDescription (SBD) format such as for a Session-Based Dynamic AdaptiveStreaming over HTTP (DASH) operation standard (ISO/IEC 23009-8).

2. Description of Related Art

The Moving Picture Experts Group (MPEG) has recently started a new partin DASH standardization for Session-Based DASH Operation. In such asession, while the media presentation description (MPD) is generic forall clients, a client may get a side file, so called SBD, which providesinstructions for the client to make MPD specific for that session.However, there is a technical problem arising in such field in whichthere may not be functionality beyond at most adding queries to segmentuniform resource locators (URLs).

SUMMARY

To address one or more different technical problems, this disclosureprovides technical solutions improving such functionality.

There is included a method and apparatus comprising memory configured tostore computer program code and a processor or processors configured toaccess the computer program code and operate as instructed by thecomputer program code. The computer program code includes obtaining codeconfigured to cause the at least one processor to obtain session-baseddescription (SBD) information instructing a client to generate mediapresentation description (MPD) information of a session, launching codeconfigured to cause the at least one processor to launch an SBD clientand passing SBD descriptor information based on the MPD information,controlling code configured to cause the at least one processor tocontrol generation of a segment uniform resource locator (URL),provision of a timing; and processing of a request for a segment of thevideo content by at least modifying the segment URL, and providing codeconfigured to cause the at least one processor to provide a segment ofthe video content based on the modified segment URL.

According to exemplary embodiments, the SBD information comprises a URLvalue, a template value, and a key value.

According to exemplary embodiments, there is generating code configuredto cause the at least one hardware processor to generate the modifiedsegment URL based on the SBD information.

According to exemplary embodiments, there is determining code configuredto cause the at least one hardware processor to determine whether userinformation is indicated in the SBD information, and, when the userinformation is indicated in the SBD information, to modify the segmentURL by replacing at least a string in a user information template of theSBD information.

According to exemplary embodiments, there is determining code configuredto cause the at least one hardware processor to determine whether hostinformation is indicated in the SBD information, and, when the hostinformation is indicated in the SBD information, to modify the segmentURL by replacing at least a string in a host information template of theSBD information.

According to exemplary embodiments, there is determining code configuredto cause the at least one hardware processor to determine whether portinformation is indicated in the SBD information, and, when the portinformation is indicated in the SBD information, to modify the segmentURL by replacing at least a string in a port information template of theSBD information.

According to exemplary embodiments, there is determining code configuredto cause the at least one hardware processor to determine whether pathinformation is indicated in the SBD information, and, when the pathinformation is indicated in the SBD information, to modify the segmentURL by replacing at least a string in a path information template of theSBD information.

According to exemplary embodiments, generating the modified segment URLcomprises modifying at least one authority field of the segment URL.

According to exemplary embodiments, generating the modified segment URLcomprises modifying at least one path field of the segment URL.

According to exemplary embodiments, generating the modified segment URLcomprises modifying at least one authority field and one path field ofthe segment URL.

BRIEF DESCRIPTION OF THE DRAWINGS

Further features, nature, and various advantages of the disclosedsubject matter will be more apparent from the following detaileddescription and the accompanying drawings in which:

FIG. 1 is a simplified schematic illustration in accordance withembodiments.

FIG. 2 is a simplified schematic illustration in accordance withembodiments.

FIG. 3 is a simplified block diagram regarding decoders in accordancewith embodiments.

FIG. 4 is a simplified block diagram regarding encoders in accordancewith embodiments.

FIG. 5 is a simplified block diagram in accordance with embodiments.

FIG. 6 is a simplified flow chart in accordance with embodiments.

FIG. 7 is a simplified flow chart in accordance with embodiments.

FIG. 8 is a schematic illustration in accordance with embodiments.

DETAILED DESCRIPTION

The proposed features discussed below may be used separately or combinedin any order. Further, the embodiments may be implemented by processingcircuitry (e.g., one or more processors or one or more integratedcircuits). In one example, the one or more processors execute a programthat is stored in a non-transitory computer-readable medium.

FIG. 1 illustrates a simplified block diagram of a communication system100 according to an embodiment of the present disclosure. Thecommunication system 100 may include at least two terminals 102 and 103interconnected via a network 105. For unidirectional transmission ofdata, a first terminal 103 may code video data at a local location fortransmission to the other terminal 102 via the network 105. The secondterminal 102 may receive the coded video data of the other terminal fromthe network 105, decode the coded data and display the recovered videodata. Unidirectional data transmission may be common in media servingapplications and the like.

FIG. 1 illustrates a second pair of terminals 101 and 104 provided tosupport bidirectional transmission of coded video that may occur, forexample, during videoconferencing. For bidirectional transmission ofdata, each terminal 101 and 104 may code video data captured at a locallocation for transmission to the other terminal via the network 105.Each terminal 101 and 104 also may receive the coded video datatransmitted by the other terminal, may decode the coded data and maydisplay the recovered video data at a local display device.

In FIG. 1, the terminals 101, 102, 103 and 104 may be illustrated asservers, personal computers and smart phones but the principles of thepresent disclosure are not so limited. Embodiments of the presentdisclosure find application with laptop computers, tablet computers,media players and/or dedicated video conferencing equipment. The network105 represents any number of networks that convey coded video data amongthe terminals 101, 102, 103 and 104, including for example wirelineand/or wireless communication networks. The communication network 105may exchange data in circuit-switched and/or packet-switched channels.Representative networks include telecommunications networks, local areanetworks, wide area networks and/or the Internet. For the purposes ofthe present discussion, the architecture and topology of the network 105may be immaterial to the operation of the present disclosure unlessexplained herein below.

FIG. 2 illustrates, as an example for an application for the disclosedsubject matter, the placement of a video encoder and decoder in astreaming environment. The disclosed subject matter can be equallyapplicable to other video enabled applications, including, for example,video conferencing, digital TV, storing of compressed video on digitalmedia including CD, DVD, memory stick and the like, and so on.

A streaming system may include a capture subsystem 203, that can includea video source 201, for example a digital camera, creating, for example,an uncompressed video sample stream 213. That sample stream 213 may beemphasized as a high data volume when compared to encoded videobitstreams and can be processed by an encoder 202 coupled to the camera201. The encoder 202 can include hardware, software, or a combinationthereof to enable or implement aspects of the disclosed subject matteras described in more detail below. The encoded video bitstream 204,which may be emphasized as a lower data volume when compared to thesample stream, can be stored on a streaming server 205 for future use.One or more streaming clients 212 and 207 can access the streamingserver 205 to retrieve copies 208 and 206 of the encoded video bitstream204. A client 212 can include a video decoder 211 which decodes theincoming copy of the encoded video bitstream 208 and creates an outgoingvideo sample stream 210 that can be rendered on a display 209 or otherrendering device (not depicted). In some streaming systems, the videobitstreams 204, 206 and 208 can be encoded according to certain videocoding/compression standards. Examples of those standards are notedabove and described further herein.

FIG. 3 may be a functional block diagram of a video decoder 300according to an embodiment of the present invention.

A receiver 302 may receive one or more codec video sequences to bedecoded by the decoder 300; in the same or another embodiment, one codedvideo sequence at a time, where the decoding of each coded videosequence is independent from other coded video sequences. The codedvideo sequence may be received from a channel 301, which may be ahardware/software link to a storage device which stores the encodedvideo data. The receiver 302 may receive the encoded video data withother data, for example, coded audio data and/or ancillary data streams,that may be forwarded to their respective using entities (not depicted).The receiver 302 may separate the coded video sequence from the otherdata. To combat network jitter, a buffer memory 303 may be coupled inbetween receiver 302 and entropy decoder/parser 304 (“parser”henceforth). When receiver 302 is receiving data from a store/forwarddevice of sufficient bandwidth and controllability, or from anisosychronous network, the buffer 303 may not be needed, or can besmall. For use on best effort packet networks such as the Internet, thebuffer 303 may be required, can be comparatively large and canadvantageously of adaptive size.

The video decoder 300 may include a parser 304 to reconstruct symbols313 from the entropy coded video sequence. Categories of those symbolsinclude information used to manage operation of the decoder 300, andpotentially information to control a rendering device such as a display312 that is not an integral part of the decoder but can be coupled toit. The control information for the rendering device(s) may be in theform of Supplementary Enhancement Information (SEI messages) or VideoUsability Information parameter set fragments (not depicted). The parser304 may parse/entropy-decode the coded video sequence received. Thecoding of the coded video sequence can be in accordance with a videocoding technology or standard, and can follow principles well known to aperson skilled in the art, including variable length coding, Huffmancoding, arithmetic coding with or without context sensitivity, and soforth. The parser 304 may extract from the coded video sequence, a setof subgroup parameters for at least one of the subgroups of pixels inthe video decoder, based upon at least one parameters corresponding tothe group. Subgroups can include Groups of Pictures (GOPs), pictures,tiles, slices, macroblocks, Coding Units (CUs), blocks, Transform Units(TUs), Prediction Units (PUs) and so forth. The entropy decoder/parsermay also extract from the coded video sequence information such astransform coefficients, quantizer parameter values, motion vectors, andso forth.

The parser 304 may perform entropy decoding/parsing operation on thevideo sequence received from the buffer 303, so to create symbols 313.The parser 304 may receive encoded data, and selectively decodeparticular symbols 313. Further, the parser 304 may determine whetherthe particular symbols 313 are to be provided to a Motion CompensationPrediction unit 306, a scaler/inverse transform unit 305, an IntraPrediction Unit 307, or a loop filter 311.

Reconstruction of the symbols 313 can involve multiple different unitsdepending on the type of the coded video picture or parts thereof (suchas: inter and intra picture, inter and intra block), and other factors.Which units are involved, and how, can be controlled by the subgroupcontrol information that was parsed from the coded video sequence by theparser 304. The flow of such subgroup control information between theparser 304 and the multiple units below is not depicted for clarity.

Beyond the functional blocks already mentioned, decoder 300 can beconceptually subdivided into a number of functional units as describedbelow. In a practical implementation operating under commercialconstraints, many of these units interact closely with each other andcan, at least partly, be integrated into each other. However, for thepurpose of describing the disclosed subject matter, the conceptualsubdivision into the functional units below is appropriate.

A first unit is the scaler/inverse transform unit 305. Thescaler/inverse transform unit 305 receives quantized transformcoefficient as well as control information, including which transform touse, block size, quantization factor, quantization scaling matrices,etc. as symbol(s) 313 from the parser 304. It can output blockscomprising sample values, that can be input into aggregator 310.

In some cases, the output samples of the scaler/inverse transform 305can pertain to an intra coded block; that is: a block that is not usingpredictive information from previously reconstructed pictures, but canuse predictive information from previously reconstructed parts of thecurrent picture. Such predictive information can be provided by an intrapicture prediction unit 307. In some cases, the intra picture predictionunit 307 generates a block of the same size and shape of the block underreconstruction, using surrounding already reconstructed informationfetched from the current (partly reconstructed) picture 309. Theaggregator 310, in some cases, adds, on a per sample basis, theprediction information the intra prediction unit 307 has generated tothe output sample information as provided by the scaler/inversetransform unit 305.

In other cases, the output samples of the scaler/inverse transform unit305 can pertain to an inter coded, and potentially motion compensatedblock. In such a case, a Motion Compensation Prediction unit 306 canaccess reference picture memory 308 to fetch samples used forprediction. After motion compensating the fetched samples in accordancewith the symbols 313 pertaining to the block, these samples can be addedby the aggregator 310 to the output of the scaler/inverse transform unit(in this case called the residual samples or residual signal) so togenerate output sample information. The addresses within the referencepicture memory form where the motion compensation unit fetchesprediction samples can be controlled by motion vectors, available to themotion compensation unit in the form of symbols 313 that can have, forexample X, Y, and reference picture components. Motion compensation alsocan include interpolation of sample values as fetched from the referencepicture memory when sub-sample exact motion vectors are in use, motionvector prediction mechanisms, and so forth.

The output samples of the aggregator 310 can be subject to various loopfiltering techniques in the loop filter unit 311. Video compressiontechnologies can include in-loop filter technologies that are controlledby parameters included in the coded video bitstream and made availableto the loop filter unit 311 as symbols 313 from the parser 304, but canalso be responsive to meta-information obtained during the decoding ofprevious (in decoding order) parts of the coded picture or coded videosequence, as well as responsive to previously reconstructed andloop-filtered sample values.

The output of the loop filter unit 311 can be a sample stream that canbe output to the render device 312 as well as stored in the referencepicture memory 557 for use in future inter-picture prediction.

Certain coded pictures, once fully reconstructed, can be used asreference pictures for future prediction. Once a coded picture is fullyreconstructed and the coded picture has been identified as a referencepicture (by, for example, parser 304), the current reference picture 309can become part of the reference picture buffer 308, and a fresh currentpicture memory can be reallocated before commencing the reconstructionof the following coded picture.

The video decoder 300 may perform decoding operations according to apredetermined video compression technology that may be documented in astandard, such as ITU-T Rec. H.265. The coded video sequence may conformto a syntax specified by the video compression technology or standardbeing used, in the sense that it adheres to the syntax of the videocompression technology or standard, as specified in the videocompression technology document or standard and specifically in theprofiles document therein. Also necessary for compliance can be that thecomplexity of the coded video sequence is within bounds as defined bythe level of the video compression technology or standard. In somecases, levels restrict the maximum picture size, maximum frame rate,maximum reconstruction sample rate (measured in, for example megasamplesper second), maximum reference picture size, and so on. Limits set bylevels can, in some cases, be further restricted through HypotheticalReference Decoder (HRD) specifications and metadata for HRD buffermanagement signaled in the coded video sequence.

In an embodiment, the receiver 302 may receive additional (redundant)data with the encoded video. The additional data may be included as partof the coded video sequence(s). The additional data may be used by thevideo decoder 300 to properly decode the data and/or to more accuratelyreconstruct the original video data. Additional data can be in the formof, for example, temporal, spatial, or signal-to-noise ratio (SNR)enhancement layers, redundant slices, redundant pictures, forward errorcorrection codes, and so on.

FIG. 4 may be a functional block diagram of a video encoder 400according to an embodiment of the present disclosure.

The encoder 400 may receive video samples from a video source 401 (thatis not part of the encoder) that may capture video image(s) to be codedby the encoder 400.

The video source 401 may provide the source video sequence to be codedby the encoder (303) in the form of a digital video sample stream thatcan be of any suitable bit depth (for example: 8 bit, 10 bit, 12 bit, .. . ), any colorspace (for example, BT.601 Y CrCB, RGB, . . . ) and anysuitable sampling structure (for example Y CrCb 4:2:0, Y CrCb 4:4:4). Ina media serving system, the video source 401 may be a storage devicestoring previously prepared video. In a videoconferencing system, thevideo source 401 may be a camera that captures local image informationas a video sequence. Video data may be provided as a plurality ofindividual pictures that impart motion when viewed in sequence. Thepictures themselves may be organized as a spatial array of pixels,wherein each pixel can comprise one or more samples depending on thesampling structure, color space, etc. in use. A person skilled in theart can readily understand the relationship between pixels and samples.The description below focuses on samples.

According to an embodiment, the encoder 400 may code and compress thepictures of the source video sequence into a coded video sequence 410 inreal time or under any other time constraints as required by theapplication. Enforcing appropriate coding speed is one function ofController 402. Controller controls other functional units as describedbelow and is functionally coupled to these units. The coupling is notdepicted for clarity. Parameters set by controller can include ratecontrol related parameters (picture skip, quantizer, lambda value ofrate-distortion optimization techniques, . . . ), picture size, group ofpictures (GOP) layout, maximum motion vector search range, and so forth.A person skilled in the art can readily identify other functions ofcontroller 402 as they may pertain to video encoder 400 optimized for acertain system design.

Some video encoders operate in what a person skilled in the art readilyrecognizes as a “coding loop.” As an oversimplified description, acoding loop can consist of the encoding part of an encoder 402 (“sourcecoder” henceforth) (responsible for creating symbols based on an inputpicture to be coded, and a reference picture(s)), and a (local) decoder406 embedded in the encoder 400 that reconstructs the symbols to createthe sample data that a (remote) decoder also would create (as anycompression between symbols and coded video bitstream is lossless in thevideo compression technologies considered in the disclosed subjectmatter). That reconstructed sample stream is input to the referencepicture memory 405. As the decoding of a symbol stream leads tobit-exact results independent of decoder location (local or remote), thereference picture buffer content is also bit exact between local encoderand remote encoder. In other words, the prediction part of an encoder“sees” as reference picture samples exactly the same sample values as adecoder would “see” when using prediction during decoding. Thisfundamental principle of reference picture synchronicity (and resultingdrift, if synchronicity cannot be maintained, for example because ofchannel errors) is well known to a person skilled in the art.

The operation of the “local” decoder 406 can be the same as of a“remote” decoder 300, which has already been described in detail abovein conjunction with FIG. 3. Briefly referring also to FIG. 4, however,as symbols are available and en/decoding of symbols to a coded videosequence by entropy coder 408 and parser 304 can be lossless, theentropy decoding parts of decoder 300, including channel 301, receiver302, buffer 303, and parser 304 may not be fully implemented in localdecoder 406.

An observation that can be made at this point is that any decodertechnology except the parsing/entropy decoding that is present in adecoder also necessarily needs to be present, in substantially identicalfunctional form, in a corresponding encoder. The description of encodertechnologies can be abbreviated as they are the inverse of thecomprehensively described decoder technologies. Only in certain areas amore detail description is required and provided below.

As part of its operation, the source coder 403 may perform motioncompensated predictive coding, which codes an input frame predictivelywith reference to one or more previously-coded frames from the videosequence that were designated as “reference frames.” In this manner, thecoding engine 407 codes differences between pixel blocks of an inputframe and pixel blocks of reference frame(s) that may be selected asprediction reference(s) to the input frame.

The local video decoder 406 may decode coded video data of frames thatmay be designated as reference frames, based on symbols created by thesource coder 403. Operations of the coding engine 407 may advantageouslybe lossy processes. When the coded video data may be decoded at a videodecoder (not shown in FIG. 4), the reconstructed video sequencetypically may be a replica of the source video sequence with someerrors. The local video decoder 406 replicates decoding processes thatmay be performed by the video decoder on reference frames and may causereconstructed reference frames to be stored in the reference picturecache 405. In this manner, the encoder 400 may store copies ofreconstructed reference frames locally that have common content as thereconstructed reference frames that will be obtained by a far-end videodecoder (absent transmission errors).

The predictor 404 may perform prediction searches for the coding engine407. That is, for a new frame to be coded, the predictor 404 may searchthe reference picture memory 405 for sample data (as candidate referencepixel blocks) or certain metadata such as reference picture motionvectors, block shapes, and so on, that may serve as an appropriateprediction reference for the new pictures. The predictor 404 may operateon a sample block-by-pixel block basis to find appropriate predictionreferences. In some cases, as determined by search results obtained bythe predictor 404, an input picture may have prediction references drawnfrom multiple reference pictures stored in the reference picture memory405.

The controller 402 may manage coding operations of the video coder 403,including, for example, setting of parameters and subgroup parametersused for encoding the video data.

Output of all aforementioned functional units may be subjected toentropy coding in the entropy coder 408. The entropy coder translatesthe symbols as generated by the various functional units into a codedvideo sequence, by loss-less compressing the symbols according totechnologies known to a person skilled in the art as, for exampleHuffman coding, variable length coding, arithmetic coding, and so forth.

The transmitter 409 may buffer the coded video sequence(s) as created bythe entropy coder 408 to prepare it for transmission via a communicationchannel 411, which may be a hardware/software link to a storage devicewhich would store the encoded video data. The transmitter 409 may mergecoded video data from the video coder 403 with other data to betransmitted, for example, coded audio data and/or ancillary data streams(sources not shown).

The controller 402 may manage operation of the encoder 400. Duringcoding, the controller 405 may assign to each coded picture a certaincoded picture type, which may affect the coding techniques that may beapplied to the respective picture. For example, pictures often may beassigned as one of the following frame types:

An Intra Picture (I picture) may be one that may be coded and decodedwithout using any other frame in the sequence as a source of prediction.Some video codecs allow for different types of Intra pictures,including, for example Independent Decoder Refresh Pictures. A personskilled in the art is aware of those variants of I pictures and theirrespective applications and features.

A Predictive picture (P picture) may be one that may be coded anddecoded using intra prediction or inter prediction using at most onemotion vector and reference index to predict the sample values of eachblock.

A Bi-directionally Predictive Picture (B Picture) may be one that may becoded and decoded using intra prediction or inter prediction using atmost two motion vectors and reference indices to predict the samplevalues of each block. Similarly, multiple-predictive pictures can usemore than two reference pictures and associated metadata for thereconstruction of a single block.

Source pictures commonly may be subdivided spatially into a plurality ofsample blocks (for example, blocks of 4×4, 8×8, 4×8, or 16×16 sampleseach) and coded on a block-by-block basis. Blocks may be codedpredictively with reference to other (already coded) blocks asdetermined by the coding assignment applied to the blocks' respectivepictures. For example, blocks of I pictures may be codednon-predictively or they may be coded predictively with reference toalready coded blocks of the same picture (spatial prediction or intraprediction). Pixel blocks of P pictures may be coded non-predictively,via spatial prediction or via temporal prediction with reference to onepreviously coded reference pictures. Blocks of B pictures may be codednon-predictively, via spatial prediction or via temporal prediction withreference to one or two previously coded reference pictures.

The video coder 400 may perform coding operations according to apredetermined video coding technology or standard, such as ITU-T Rec.H.265. In its operation, the video coder 400 may perform variouscompression operations, including predictive coding operations thatexploit temporal and spatial redundancies in the input video sequence.The coded video data, therefore, may conform to a syntax specified bythe video coding technology or standard being used.

In an embodiment, the transmitter 409 may transmit additional data withthe encoded video. The source coder 403 may include such data as part ofthe coded video sequence. Additional data may comprisetemporal/spatial/SNR enhancement layers, other forms of redundant datasuch as redundant pictures and slices, Supplementary EnhancementInformation (SEI) messages, Visual Usability Information (VUI) parameterset fragments, and so on.

FIG. 5 illustrates a simple block diagram 500 of a general session-basedDASH operation high level architecture according to exemplaryembodiments. For example, media may originate at origin 501 and byprovided to a content delivery network (CDN) 502 which may provideMPD/segments to a DASH Access Client 503. A session client 506 may becontrolled to request a value, such as by getValue (key, time) by theDASH access client 503, and such value may be provided to the DASHAccess Client 503 from the session client 506 in conjunction withcontrol from the session controllers 504 and 505 and their respectiveSBD data, such as SBD[0] n SBD [1] as in the example embodiments ofFIGS. 6 and 7. For example, there is introduced an element in the SBDdescriptor for URL templating, and, more specifically according toembodiments, SBD operations (e.g., query or URL customization) should besuch that a session client 506 can apply its processing to the segmentURL generated by the DASH access client 503, after retrieving enoughinformation from the MPD in the DASH access client 503. However, the SBDoperations shall not intercept the DASH access client 503 operation inexample embodiments, and, while example implementations may combine MPDand SBD processing, other embodiments hold that such features may bedone consequently. In this light, an advantage thereof may be that theSBD operation can be added to any DASH access client as an applicationrather than integrated with the DASH client logic.

As such, embodiments may change a URL with a new value can be added tothe following process; however, a replacement of the URL may beperformed by an SBD client. That is, see the flowchart 600 of FIG. 6according to exemplary embodiments where there may be the followingfeatures. At S602, a DASH client, such as DASH access client 503, parsesthe MPD such as from the CDN 502, and, at S603, there is performed afinding of the SBD descriptor (e.g., “getValue (key, time)”) whichlaunches the SBD client, such as session client 506, and passes the SBDdescriptor information: @value (URL), @template, key. At S603, the DASHclient for every segment requests: generate the segment URL, and atS604, there is provided the segment URL and segment timing to the SBDclient such that at S605 the SBD client processes the request, modifiesthe URL and add the query, and return the result, and at S606, the DASHclient requests at least the corresponding segment and processes andplays that segment accordingly.

For example, at S605, the following SBD URL replacement fieldinformation may be considered. Considering that a URL includes,according to exemplary embodiments, the following:

URI=scheme:[//authority]path[?query][#fragment]  (Eq. 1)

Then, since the query is already addressed, embodiments consider areplacement for the authority and path information.

According to embodiments, authority includes three fields:

authority=[userinfo@]host[:port]  (Eq. 2)

In view of such information as Eq. 1 and Eq2, embodiments includedifferent keys and templates, such as ones of four different keys andtemplates paired for each, such as shown in Table 1, which illustratesan example of MPD EssentialProperty Descriptor attributes forsession-based DASH according to exemplary embodiments, as follows:

TABLE 1 Element or Attribute Name Use Description EssentialPropertyinstantiation of EssentialProperty (defined in ISO/IEC 23009-1) forsession-based DASH operations @schemeIdUri M shall be set to“urn:mpeg:dash:sbd:2020”. (string) @value M URL of the SBD document forthis session (string) @template O template for applying to the key-valuepair found in the SBD document. When the value of a Key@name in the@template is found in the SBD document, its corresponding key-value pairof SBD document shall replace the string between unescaped ‘$’characters in the @template. The @template value shall have nowhitespace characters. If absent, Key@name and its corresponding valuein the SBD document, separated by ‘=’, shall be added to the end of thequery, where each consecutive key-value pairs are separated by ‘&’. Theorder of key-value pairs in the query is defined by the order of Keyelements in this descriptor @userinfoTemplate O userinfo template forapplying to the key-value pair found in SBD document. When the value ofa UrlKey@userinfo in the @userinfoTemplate is found in the SBD document,its corresponding value pair of SBD document shall replace the stringbetween unescaped ‘$’ characters in the @userinfoTemplate, and the URL'suserinfo is replaced with the result. The @userinfoTemplate value shallhave no whitespace characters. @hostTemplate O host template forapplying to the key-value pair found in the SBD document. When the valueof a UrlKey@hostinfo in the @hostTemplate is found in the SBD document,its corresponding value pair of SBD document shall replace the stringbetween unescaped ‘$’ characters in the @hostTemplate, and the URL'shost is replaced with the result. The @hostTemplate value shall have nowhitespace characters. @portTemplate O port template for applying to thekey-value pair found in the SBD document. When the value of aUrlKey@port in the @portTemplate is found in the SBD document, itscorresponding value pair of SBD document shall replace the stringbetween unescaped ‘$’ characters in the @portTemplate, and the URL'sport is replaced with the result. The @portTemplate value shall have nowhitespace characters. @pathTemplate O path template for applying to thekey-value pair found in the SBD document. When the value of aUrlKey@path in the @pathTemplate is found in the SBD document, itscorresponding value pair of SBD document shall replace the stringbetween unescaped ‘$’ characters in the @pathTemplate, and the URL'spath is replaced with the result. The @pathTemplate value shall have nowhitespace characters. Key 0 . . . N a key name to be found in the SBDdocument and its default value. If absent, all keys and correspondingvalues in the corresponding keyList of the SBD document shall be addedto the (sub)segment request URL query. At least one Key or one UrlKeyelement shall exist in this Essential Descriptors. @name M Name of thekey of the SBD document to be added to the queries for this sessionafter processing described by @template. This value shall be a stringwithout whitespaces, start with a letter, and contain only unreservedcharacters per RFC 3986. If @name value does not appear in the keyListof SBD document, the @name value-@defaultValue value pair shall be usedin the template or in the absence of the template. @defaultValue ODdefault value in key-value pair if @name value (‘null’) not found in SBDdocument or if there is no value defined for a requested time range orsegment number in the SBD document. UrlKey 0 . . . 1 a set of URL keysto be found in the SBD document and its default value. @userinfo O URIuserinfo key for SBD processing @host O URI host key for SBD processing@port O URI port key SBD processing @path O URI path key SBD processing@defaultUserinfo O The default userinfo if the userinfo key is not foundin SBD @defaultHost O The default host if the host key is not found inSBD @defaultPort O The default port if the port key is not found in SBD@defaultPath O The default path if the path key is not found in SBDLegend: For attributes: M = Mandatory, O = Optional, OD = Optional withDefault Value, CM = Conditionally Mandatory. For elements: <minOccurs> .. . <maxOccurs> (N = unbounded) Elements are bold; attributes arenon-bold and preceded with an @.

FIG. 7 illustrates and exemplary flowchart 700 in which at S701 there isa determining of a UrlKeyvalue as noted above and further explainedherein where, at S702, S704, S706, and S708 there may be respectivedeterminations, in sequence and/or in parallel, whether there arerespectively any of UrlKey@userinfo at S702, UrlKey@hostinfo at S704,UrlKey@port at S706, and UrlKey@path.

At S702, a userinfo template for applying to the key-value pair found ina SBD document is considered such that when the value of aUrlKey@userinfo in the @userinfoTemplate is found in the SBD document,its corresponding value pair of SBD document shall replace the stringbetween unescaped ‘$’ characters in the @userinfoTemplate, and the URL'suserinfo is replaced with the result at S703. The @userinfoTemplatevalue shall have no whitespace characters according to exemplaryembodiments.

At S704, a host template for applying to the key-value pair found in theSBD document is considered such that when the value of a UrlKey@hostinfoin the @hostTemplate is found in the SBD document, its correspondingvalue pair of SBD document shall replace the string between unescaped‘$’ characters in the @hostTemplate, and the URL's host is replaced withthe result at S705. The @hostTemplate value shall have no whitespacecharacters according to exemplary embodiments.

At S706, a port template for applying to the key-value pair found in theSBD document is considered such that when the value of a UrlKey@port inthe @portTemplate is found in the SBD document, its corresponding valuepair of SBD document shall replace the string between unescaped ‘$’characters in the @portTemplate, and the URL's port is replaced with theresult at S707. The @portTemplate value shall have no whitespacecharacters according to exemplary embodiments.

At S708, a path template for applying to the key-value pair found in theSBD document is considered such that when the value of a UrlKey@path inthe @pathTemplate is found in the SBD document, its corresponding valuepair of SBD document shall replace the string between unescaped ‘$’characters in the @pathTemplate, and the URL's path is replaced with theresult at S709. The @pathTemplate value shall have no whitespacecharacters.

According to exemplary embodiments with respect to FIG. 7, note that anysegment URL of any element that itself or its parent(s) includes an SBDdescriptor shall be processed by a SBD client for URL replacementaccording to exemplary embodiments.

MPEG-DASH generally referred to an adaptive bitrate streaming techniquethat enables streaming of media content over the Internet delivered fromconventional HTTP web servers. A media presentation description (MPD)file is used to hold the information on the various streams and thebandwidths they are associated with. In view of the above describedembodiments, in DASH, although the MPD may be generic for all clients, aclient may get a side file, also referred to as Session-BasedDescription (SBD), which provides instructions for the client to makemedia presentation description (MPD) specific for that session. Herein,there are embodiment where features are included such that not only mayqueries be added to segment URLs, but such embodiments herein alsoprovide a technical solution to Session-Based DASH operations, which maybe an important approach to customize the MPD per session and possiblyper client, for improvements such that the query parameters in each SBDsession may be added and further the SBD session may be customized suchthat the segment URL may use the SBD information as described above.

Such technical advantages may be achieved with respect to the aboveembodiments in which there are methods described to customize thesegment URLs using Session-Based Description file, wherein thecustomization is done after the DASH client generates the segment URL,wherein the customization may happen on all authority and path fields ofthe URL, wherein each field has a template and a key, and when the keymatch is found in the right time or order line of the SBD file, thecorresponding value of the key in the SBD file is used for modificationof the corresponding template, wherein the customization of the URL ispossible with flexibility in every single field, wherein the segmentsURLs are customized which belong to the parent element with SBDessential descriptor, wherein a different SBD file can be used perparent element according to exemplary embodiments.

The techniques described above, can be implemented as computer softwareusing computer-readable instructions and physically stored in one ormore computer-readable media or by a specifically configured one or morehardware processors. For example, FIG. 8 shows a computer system 800suitable for implementing certain embodiments of the disclosed subjectmatter.

The computer software can be coded using any suitable machine code orcomputer language, that may be subject to assembly, compilation,linking, or like mechanisms to create code comprising instructions thatcan be executed directly, or through interpretation, micro-codeexecution, and the like, by computer central processing units (CPUs),Graphics Processing Units (GPUs), and the like.

The instructions can be executed on various types of computers orcomponents thereof, including, for example, personal computers, tabletcomputers, servers, smartphones, gaming devices, internet of thingsdevices, and the like.

The components shown in FIG. 8 for computer system 800 are exemplary innature and are not intended to suggest any limitation as to the scope ofuse or functionality of the computer software implementing embodimentsof the present disclosure. Neither should the configuration ofcomponents be interpreted as having any dependency or requirementrelating to any one or combination of components illustrated in theexemplary embodiment of a computer system 800.

Computer system 800 may include certain human interface input devices.Such a human interface input device may be responsive to input by one ormore human users through, for example, tactile input (such as:keystrokes, swipes, data glove movements), audio input (such as: voice,clapping), visual input (such as: gestures), olfactory input (notdepicted). The human interface devices can also be used to capturecertain media not necessarily directly related to conscious input by ahuman, such as audio (such as: speech, music, ambient sound), images(such as: scanned images, photographic images obtain from a still imagecamera), video (such as two-dimensional video, three-dimensional videoincluding stereoscopic video).

Input human interface devices may include one or more of (only one ofeach depicted): keyboard 801, mouse 802, trackpad 803, touch screen 810,joystick 805, microphone 806, scanner 808, camera 807.

Computer system 800 may also include certain human interface outputdevices. Such human interface output devices may be stimulating thesenses of one or more human users through, for example, tactile output,sound, light, and smell/taste. Such human interface output devices mayinclude tactile output devices (for example tactile feedback by thetouch-screen 810, or joystick 805, but there can also be tactilefeedback devices that do not serve as input devices), audio outputdevices (such as: speakers 809, headphones (not depicted)), visualoutput devices (such as screens 810 to include CRT screens, LCD screens,plasma screens, OLED screens, each with or without touch-screen inputcapability, each with or without tactile feedback capability—some ofwhich may be capable to output two dimensional visual output or morethan three dimensional output through means such as stereographicoutput; virtual-reality glasses (not depicted), holographic displays andsmoke tanks (not depicted)), and printers (not depicted).

Computer system 800 can also include human accessible storage devicesand their associated media such as optical media including CD/DVD ROM/RW820 with CD/DVD 811 or the like media, thumb-drive 822, removable harddrive or solid state drive 823, legacy magnetic media such as tape andfloppy disc (not depicted), specialized ROM/ASIC/PLD based devices suchas security dongles (not depicted), and the like.

Those skilled in the art should also understand that term “computerreadable media” as used in connection with the presently disclosedsubject matter does not encompass transmission media, carrier waves, orother transitory signals.

Computer system 800 can also include interface 899 to one or morecommunication networks 898. Networks 898 can for example be wireless,wireline, optical. Networks 898 can further be local, wide-area,metropolitan, vehicular and industrial, real-time, delay-tolerant, andso on. Examples of networks 998 include local area networks such asEthernet, wireless LANs, cellular networks to include GSM, 3G, 4G, 5G,LTE and the like, TV wireline or wireless wide area digital networks toinclude cable TV, satellite TV, and terrestrial broadcast TV, vehicularand industrial to include CANBus, and so forth. Certain networks 898commonly require external network interface adapters that attached tocertain general-purpose data ports or peripheral buses (850 and 851)(such as, for example USB ports of the computer system 800; others arecommonly integrated into the core of the computer system 800 byattachment to a system bus as described below (for example Ethernetinterface into a PC computer system or cellular network interface into asmartphone computer system). Using any of these networks 898, computersystem 800 can communicate with other entities. Such communication canbe uni-directional, receive only (for example, broadcast TV),uni-directional send-only (for example CANbusto certain CANbus devices),or bi-directional, for example to other computer systems using local orwide area digital networks. Certain protocols and protocol stacks can beused on each of those networks and network interfaces as describedabove.

Aforementioned human interface devices, human-accessible storagedevices, and network interfaces can be attached to a core 840 of thecomputer system 800.

The core 840 can include one or more Central Processing Units (CPU) 841,Graphics Processing Units (GPU) 842, a graphics adapter 817, specializedprogrammable processing units in the form of Field Programmable GateAreas (FPGA) 843, hardware accelerators for certain tasks 844, and soforth. These devices, along with Read-only memory (ROM) 845,Random-access memory 846, internal mass storage such as internalnon-user accessible hard drives, SSDs, and the like 847, may beconnected through a system bus 848. In some computer systems, the systembus 848 can be accessible in the form of one or more physical plugs toenable extensions by additional CPUs, GPU, and the like. The peripheraldevices can be attached either directly to the core's system bus 848, orthrough a peripheral bus 851. Architectures for a peripheral bus includePCI, USB, and the like.

CPUs 841, GPUs 842, FPGAs 843, and accelerators 844 can execute certaininstructions that, in combination, can make up the aforementionedcomputer code. That computer code can be stored in ROM 845 or RAM 846.Transitional data can be also be stored in RAM 846, whereas permanentdata can be stored for example, in the internal mass storage 847. Faststorage and retrieval to any of the memory devices can be enabledthrough the use of cache memory, that can be closely associated with oneor more CPU 841, GPU 842, mass storage 847, ROM 845, RAM 846, and thelike.

The computer readable media can have computer code thereon forperforming various computer-implemented operations. The media andcomputer code can be those specially designed and constructed for thepurposes of the present disclosure, or they can be of the kind wellknown and available to those having skill in the computer software arts.

As an example and not by way of limitation, the computer system havingarchitecture 800, and specifically the core 840 can providefunctionality as a result of processor(s) (including CPUs, GPUs, FPGA,accelerators, and the like) executing software embodied in one or moretangible, computer-readable media. Such computer-readable media can bemedia associated with user-accessible mass storage as introduced above,as well as certain storage of the core 840 that are of non-transitorynature, such as core-internal mass storage 847 or ROM 845. The softwareimplementing various embodiments of the present disclosure can be storedin such devices and executed by core 840. A computer-readable medium caninclude one or more memory devices or chips, according to particularneeds. The software can cause the core 840 and specifically theprocessors therein (including CPU, GPU, FPGA, and the like) to executeparticular processes or particular parts of particular processesdescribed herein, including defining data structures stored in RAM 846and modifying such data structures according to the processes defined bythe software. In addition or as an alternative, the computer system canprovide functionality as a result of logic hardwired or otherwiseembodied in a circuit (for example: accelerator 844), which can operatein place of or together with software to execute particular processes orparticular parts of particular processes described herein. Reference tosoftware can encompass logic, and vice versa, where appropriate.Reference to a computer-readable media can encompass a circuit (such asan integrated circuit (IC)) storing software for execution, a circuitembodying logic for execution, or both, where appropriate. The presentdisclosure encompasses any suitable combination of hardware andsoftware.

While this disclosure has described several exemplary embodiments, thereare alterations, permutations, and various substitute equivalents, whichfall within the scope of the disclosure. It will thus be appreciatedthat those skilled in the art will be able to devise numerous systemsand methods which, although not explicitly shown or described herein,embody the principles of the disclosure and are thus within the spiritand scope thereof.

What is claimed is:
 1. A method for providing video content, the methodperformed by at least one processor and comprising: obtainingsession-based description (SBD) information instructing a client togenerate media presentation description (MPD) information of a session;launching an SBD client and passing SBD descriptor information based onthe MPD information; controlling generation of a segment uniformresource locator (URL), provision of a timing; and processing of arequest for a segment of the video content by at least modifying thesegment URL; and providing a segment of the video content based on themodified segment URL.
 2. The method according to claim 1, wherein theSBD information comprises a URL value, a template value, and a keyvalue.
 3. The method according to claim 2, further comprising generatingthe modified segment URL based on the SBD information.
 4. The methodaccording to claim 3, further comprising: determining whether userinformation is indicated in the SBD information; and when the userinformation is indicated in the SBD information, modifying the segmentURL by replacing at least a string in a user information template of theSBD information.
 5. The method according to claim 3, further comprising:determining whether host information is indicated in the SBDinformation; and when the host information is indicated in the SBDinformation, modifying the segment URL by replacing at least a string ina host information template of the SBD information.
 6. The methodaccording to claim 3, further comprising: determining whether portinformation is indicated in the SBD information; and when the portinformation is indicated in the SBD information, modifying the segmentURL by replacing at least string in a port information template of theSBD information.
 7. The method according to claim 3, further comprising:determining whether path information is indicated in the SBDinformation; and when the path information is indicated in the SBDinformation, modifying the segment URL by replacing a string in a pathinformation template of the SBD information.
 8. The method according toclaim 3, wherein generating the modified segment URL comprises modifyingat least one authority field of the segment URL
 9. The method accordingto claim 3, wherein generating the modified segment URL comprisesmodifying at least one path field of the segment URL.
 10. The methodaccording to claim 3, wherein generating the modified segment URLcomprises modifying at least one path field and at least one authorityfield of the segment URL.
 11. An apparatus for providing video content,the apparatus comprising: at least one memory configured to storecomputer program code; at least one processor configured to access thecomputer program code and operate as instructed by the computer programcode, the computer program code including: obtaining code configured tocause the at least one processor to obtain session-based description(SBD) information instructing a client to generate media presentationdescription (MPD) information of a session; launching code configured tocause the at least one processor to launch an SBD client and passing SBDdescriptor information based on the MPD information; controlling codeconfigured to cause the at least one processor to control generation ofa segment uniform resource locator (URL), provision of a timing; andprocessing of a request for a segment of the video content by at leastmodifying the segment URL; and providing code configured to cause the atleast one processor to provide a segment of the video content based onthe modified segment URL.
 12. The apparatus according to claim 11,wherein the SBD information comprises a URL value, a template value, anda key value.
 13. The apparatus according to claim 12, further comprisinggenerating code configured to cause the at least one hardware processorto generate the modified segment URL based on the SBD information. 14.The apparatus according to claim 13, further comprising determining codeconfigured to cause the at least one hardware processor to determinewhether user information is indicated in the SBD information, and, whenthe user information is indicated in the SBD information, to modify thesegment URL by replacing at least a string in a user informationtemplate of the SBD information.
 15. The apparatus according to claim13, further comprising determining code configured to cause the at leastone hardware processor to determine whether host information isindicated in the SBD information, and, when the host information isindicated in the SBD information, to modify the segment URL by replacingat least a string in a host information template of the SBD information.16. The apparatus according to claim 13, further comprising determiningcode configured to cause the at least one hardware processor todetermine whether port information is indicated in the SBD information,and, when the port information is indicated in the SBD information, tomodify the segment URL by replacing at least a string in a portinformation template of the SBD information.
 17. The apparatus accordingto claim 13, further comprising determining code configured to cause theat least one hardware processor to determine whether path information isindicated in the SBD information, and, when the path information isindicated in the SBD information, to modify the segment URL by replacingat least a string in a path information template of the SBD information.18. The apparatus according to claim 13, wherein generating the modifiedsegment URL comprises modifying at least one authority field of thesegment URL.
 19. The apparatus according to claim 13, wherein generatingthe modified segment URL comprises modifying at least one path field ofthe segment URL.
 20. A non-transitory computer readable medium storing aprogram causing a computer to execute a process, the process comprising:obtaining session-based description (SBD) information instructing aclient to generate media presentation description (MPD) information of asession; launching an SBD client and passing SBD descriptor informationbased on the MPD information; controlling generation of a segmentuniform resource locator (URL), provision of a timing; and processing ofa request for a segment of the video content by at least modifying thesegment URL; and providing a segment of the video content based on themodified segment URL.